def add_two_bunbers(a, b):
    return a + b


print(add_two_bunbers(10, 20))


def is_prime(n):
    if n <= 1:
        return False
    for i in range(2, int(n ** 0.5) + 1):
        if n % i == 0:
            return False
    return True


print(is_prime(23))


def factorial(n):
    if n == 0:
        return 1
    else:
        return n * factorial(n - 1)


print(factorial(5))


